Merge branch 'akpm' (fixes from Andrew Morton)

[sfrench/cifs-2.6.git] / fs / buffer.c

diff --git a/fs/buffer.c b/fs/buffer.c
index 3588a80854b27acb18d185d437662d03668eddae..44c14a87750e7780ecb34468e60ed77b61628bf3 100644 (file)
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -1253,7 +1253,7 @@ static struct buffer_head *__bread_slow(struct buffer_head *bh)
  * a local interrupt disable for that.
  */
 
-#define BH_LRU_SIZE    8
+#define BH_LRU_SIZE    16
 
 struct bh_lru {
        struct buffer_head *bhs[BH_LRU_SIZE];
@@ -2956,7 +2956,7 @@ static void end_bio_bh_io_sync(struct bio *bio, int err)
 
 /*
  * This allows us to do IO even on the odd last sectors
- * of a device, even if the bh block size is some multiple
+ * of a device, even if the block size is some multiple
  * of the physical sector size.
  *
  * We'll just truncate the bio to the size of the device,
@@ -2966,10 +2966,11 @@ static void end_bio_bh_io_sync(struct bio *bio, int err)
  * errors, this only handles the "we need to be able to
  * do IO at the final sector" case.
  */
-static void guard_bh_eod(int rw, struct bio *bio, struct buffer_head *bh)
+void guard_bio_eod(int rw, struct bio *bio)
 {
        sector_t maxsector;
-       unsigned bytes;
+       struct bio_vec *bvec = &bio->bi_io_vec[bio->bi_vcnt - 1];
+       unsigned truncated_bytes;
 
        maxsector = i_size_read(bio->bi_bdev->bd_inode) >> 9;
        if (!maxsector)
@@ -2984,23 +2985,20 @@ static void guard_bh_eod(int rw, struct bio *bio, struct buffer_head *bh)
                return;
 
        maxsector -= bio->bi_iter.bi_sector;
-       bytes = bio->bi_iter.bi_size;
-       if (likely((bytes >> 9) <= maxsector))
+       if (likely((bio->bi_iter.bi_size >> 9) <= maxsector))
                return;
 
-       /* Uhhuh. We've got a bh that straddles the device size! */
-       bytes = maxsector << 9;
+       /* Uhhuh. We've got a bio that straddles the device size! */
+       truncated_bytes = bio->bi_iter.bi_size - (maxsector << 9);
 
        /* Truncate the bio.. */
-       bio->bi_iter.bi_size = bytes;
-       bio->bi_io_vec[0].bv_len = bytes;
+       bio->bi_iter.bi_size -= truncated_bytes;
+       bvec->bv_len -= truncated_bytes;
 
        /* ..and clear the end of the buffer for reads */
        if ((rw & RW_MASK) == READ) {
-               void *kaddr = kmap_atomic(bh->b_page);
-               memset(kaddr + bh_offset(bh) + bytes, 0, bh->b_size - bytes);
-               kunmap_atomic(kaddr);
-               flush_dcache_page(bh->b_page);
+               zero_user(bvec->bv_page, bvec->bv_offset + bvec->bv_len,
+                               truncated_bytes);
        }
 }
 
@@ -3041,7 +3039,7 @@ int _submit_bh(int rw, struct buffer_head *bh, unsigned long bio_flags)
        bio->bi_flags |= bio_flags;
 
        /* Take care of bh's that straddle the end of the device */
-       guard_bh_eod(rw, bio, bh);
+       guard_bio_eod(rw, bio);
 
        if (buffer_meta(bh))
                rw |= REQ_META;